The present invention relates to chairs and in particular to stackable chairs of the type frequently used in convention centers, banquet halls, cafeterias, assembly rooms and the like. More specifically, the invention relates to chair configurations in which a chair back has a pre-selected angle with respect to rear legs of the chair, and the invention also relates to methods of easily, and with certainty, achieving such a pre-selected angle.
Conventional stackable chairs generally comprise a seat mounted upon a frame, at an appropriate orientation for use by a person desiring to sit on the chair, and a chair back extending generally upwardly and rearwardly from the chair seat, for use as a backrest. Generally, the angle between the backrest and the chair seat is important because it is related to the comfort of a person sitting on the chair.
Most conventional chairs have four legs, a front pair of legs and a rear pair of legs. Generally, the legs extend downwardly and outwardly from the chair seat. Such chairs often have a plane of symmetry with right and left symmetrical sides, which are mirror images of each other.
As the name implies, stackable chairs are generally capable of nesting with one another, with one chair being stacked upon another. This enables easy storage and shipping. It is preferred that the chair structure not include features which would either inhibit ease of stackability or generally cause damage to one of the chairs during stacking.
Frequently, the frames of conventional stackable chairs include tubular pieces appropriately bent for use in a chair frame. Generally, each bend requires the use of a die, so that all chairs will be uniformly constructed and easily capable of stacking with one another. In some conventional chairs, numerous, different, bends have been necessary, requiring several expensive bending operations.
In some conventional chairs, the bent frame members have relatively elaborate configurations and could be both hard to form and hard to manipulate. Further, if numerous pieces are necessary, chair construction can become more expensive.
Another problem resulting from relatively complex chair frame configurations, and the use of numerous pieces in forming chair frames, is that the frames may lose their overall strength with each added bend, weld or mechanical connection. This can lead to an increased chance of structure failure during use.
With conventional chair designs, a chair back and chair seat are usually mounted on a tubular chair frame. Often, more complex chair frames may make mounting of the chair seat or chair back more difficult. Also, proper orientation of the chair back with respect to the chair seat, may necessitate relatively complex mounting means.
The above problems have never been satisfactorily addressed by chair designs, until the present invention, in a chair which is both relatively inexpensive to produce and easy to assemble.